Carabiners are typically associated with outdoor recreational activities, such as rock climbing, mountaineering, and mountain rescue work. Carabiners are also employed in many other applications, such as rescue work in urban and industrial settings, safety restraints in urban and industrial settings, law enforcement work, and military applications.
A carabiner typically includes an incomplete loop of rigid material with a gate that completes the loop. The gate may be opened to insert a rope, sling, or a belay/rappel device. The gate is typically biased by a spring to the closed position. The gate may also be secured in a closed position by a locking mechanism.
Many potentially unsafe scenarios can arise when using a traditional carabiner. As illustrated in FIG. 1, the locking carabiner 100 attaches belay device 122 to belay loop 119 on climbing harness 114. Rope 124 is threaded through the belay device 122 in a manner to enable a controlled rappel by the climber. The carabiner 100 is rotated in the belay loop 119 causing the belay device 122 to load the carabiner 100 along weaker minor axis 108. The belay device 122 is bearing directly against the screw locking mechanism 112 and the gate 104. The cross-loaded configuration illustrated in FIG. 1 may cause the screw locking mechanism 112 and/or the gate 104 to break, potentially having catastrophic consequences for the climber.
European Patent Application EP 0976936 discloses carabiner 126 having a generally C-shaped body 128, a gate 130 with a locking mechanism 138, and a lateral support member 132 as illustrated in FIGS. 2 and 3. The locking mechanism 138 is moved upward in direction 140 and screwed in direction 142 to securely lock the gate 130. The lateral support member 132 rotates about the spine of the C-shaped body 128 and snaps over the gate 130 and the locking mechanism 138 to divide opening 150 into a first portion 144 and a second portion 145. The carabiner disclosed in EP 0976936 corresponds generally to a carabiner sold under the name “Belay Master” by DMM International of Great Britain.
As illustrated in FIG. 3, first portion 144 of opening 150 is attached to a belay loop 146 of a climbing harness. Rope 148 and belay/rappel device 152 are threaded through second portion 145 of the opening 150. The lateral support member 132 prevents the carabiner 126 from rotating in the belay loop 146 to an orientation such that it may be cross-loaded along its minor axis. Furthermore, because the lateral support member 132 covers the gate 130, it is protected from another object (e.g., another carabiner, etc.) from bearing directly against the gate 130.
Operating the carabiner 126 requires two sequential steps. The gate 130 cannot be opened unless the lateral support member 132 is first disengaged. The belay loop 146 and rope 148 must all be located in the opening 150 before the lateral support member 132 can be engaged with the gate 130. That is, the user can not access portion 145 of the opening 150 without disengaging the lateral support member 132. As a result, there is a risk that the belay loop 146 and/or rope 148 may end up in the wrong portions (i.e., 144 or 145) of the opening 150. Also, the lateral support member 132 rotates perpendicular to the plane of the carabiner 126, while the gate 130 moves in the plane of the carabiner 126. Manipulating the carabiner 126 in two planes is more difficult than a single plane of operation, especially while wearing gloves. The protruding lateral support member 132 may also interfere with other climbing equipment.
U.S. Publication No. US2003/0167608 (hereinafter “the '608 Application”) discloses carabiner 154 with a generally C-shaped body 156 and a gate 158 that pivots about pin 164, as illustrated in FIGS. 4 and 5. The locking mechanism 160 includes lateral support member 162 extending from the gate 158 and engaging spine 174 of the C-shaped body 156. When the gate 158 is closed and the lateral support member 162 rotates back into the plane of the body 156 and divides opening 161 into first portion 172 and second portion 173.
As illustrated in FIG. 5, in order to open the carabiner 154, the locking mechanism 160 must be released and rotated in direction 170. As a result, the user can not access the portion 173 of the opening 161 without disengaging the lateral support member 162. All the belay devices, ropes, and harness loops must be located in the opening 161 before the lateral support member 162 is engaged, creating the risk that these elements end up in the wrong portions (i.e., 172 or 173) of the opening 161. Also, the lateral support member 162 rotates outside of the plane of the C-shape body 156, creating handling problems and potentially interfering with other climbing equipment. Finally, there is a potential danger that a climber may inadvertently sandwich the belay loop of a climbing harness between the body 156 and the lateral support member 162, thereby increasing the risk of cross-loading.
U.S. Pat. No. 7,228,601 (Thompson) discloses various embodiments of anti-cross loading features for carabiners. FIG. 6 illustrates carabiner 176 having a generally C-shaped body 178, a gate 182 including a locking mechanism 188, and a lateral support member 194. The gate 182 is secured to end region 184 of the body 178 by a pin 200 (e.g., a rivet, screw, etc.). The gate 182 is rotatable about pin 200 to enable the gate 182 to open and close manually along the general arc 189. In the closed position depicted in FIG. 6, a slot in the gate 182 receives an end region 186 of the body 178.
The lateral support member 194 divides the opening 180 into a first portion 190 and a second portion 192. The lateral support member 194 can be opened by urging it upward in axial direction 206 along the longitudinal slot 205 until the securing element 196 bears against base of lateral slot segment 203 of the L-shaped slot 202. The dimensions of the lateral support member 194 are such that when it is moved upward it does not interfere with the gate 182 in the closed position. The lateral support member 194 may then be rotated in the direction 204 within an arc provided by the lateral slot segment 203.
In order to obtain access to the first portion 190, the lateral support member 194 is rotated out of the plane of the body portion 178. The gate 182 is operated separately from the lateral support member 194 in a two-step process. In particular, the carabiner 176 has two separate locking mechanisms 188, 202 for the user to operate. Because the lateral support member 194 extends between fixed locations on the body portion 178, the first portion 190 is relatively small compared to the entire opening 180, and may be inadequate for some applications.
In another embodiment of Thompson illustrated in FIG. 7, carabiner 236 has a body 178, an arm member 227′, and a locking mechanism 240. The arm member 227′, shown in a closed, locked position, is attached to the end region 184 of the body 178 and manually rotatable thereabout along an arc in direction 232. The locking mechanism 240 includes an opening 250 configured for receiving the arm member 227′. The opening 250 comprises a restricted portion 255, configured to engage a distal end 229 of the arm member 227′ to prevent rotation. The opening 250 further includes a non-restrictive portion 257, configured to enable the arm member 227′ to rotate between an open and a closed position. The locking mechanism 240 may be twisted about the elongated section 212 of the body 178 between a locking position, with the distal end 229 of the arm member 227′ engaged within the restricted portion 255 as shown, and an unlocking position, with the non-restrictive portion 257 of the opening 250 housing the distal end 229 of the arm member 227′, enabling rotation thereof.
As with the other embodiment discussed above, the arm 227′ extends between fixed locations on the body portion 178, so the first portion 252 is relatively small compared to the entire opening 250. The gate (not shown) is operated separately from the arm 227′ in a two-step process. In order to be used for belaying or rappelling applications, the gate requires a locking mechanism, so that the carabiner 236 has two separate locking mechanisms for the user to operate.